Mean and Standard Deviation The mean‚ indicated by μ (a lower case Greek mu)‚ is the statistician ’s jargon for the average value of a signal. It is found just as you would expect: add all of the samples together‚ and divide by N. It looks like this in mathematical form: In words‚ sum the values in the signal‚ xi‚ by letting the index‚ i‚ run from 0 to N-1. Then finish the calculation by dividing the sum by N. This is identical to the equation: μ =(x0 + x1 + x2 + ... + xN-1)/N. If you are not
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Standard deviation is the square root of the variance (Gravetter & Wallnau‚ 2013). It uses the mean of the distribution as a reference point and measures variability by considering the distance of each score from the mean. It is important to know the standard deviation for a given sample because it gives a measure of the standard‚ or average‚ range from the mean‚ and specifies if the scores are grouped closely around the mean or are widely scattered (Gravetter & Wallnau‚ 2013). The standard deviation
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Remington’s Steakhouse Project Brian Jones Research Methods & Applications Dr. Jones August 25‚ 2011 Table of Contents Table of Contents 2 List of Tables 3 Introduction 4 The Research Objectives 4 The Research Questions 5 Literature Review 6 Answers to Research Questions 8 Recommendations to Remington’s 15 References 18 Annotated Bibliography 19 Appendix(ces) 22 List of Tables Table 1 Demographic Description of the Average Remington’s Patron9 Table 2 Reported Income by Remington’s
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created on a graph when using a frequency distribution method for a set of data‚ splitting the mean symmetrically. There is a big difference between standard deviation and the bell curve! Standard deviation shows the difference in variation from the average; the bell curve‚ also normal distribution or Gaussian distribution‚ shows the standard deviation and is created by the normal or equal distribution of the mean among either half. The bell curve is an important distribution pattern occurring in many
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sold‚ and that units left unsold at the end of the season were sold at a loss that average 8 percent of wholesale price. Therefore‚ the stock out probability equal to 8%/(24%+8%)=25% so there are 75% probability of being less than mean+0.67*SD (standard deviation). According to z table‚ z equal to 0.67 when probability is 0.75. Therefore‚ we can calculate quantity for each style include the risk of stock out by using formulate Q*=mean+z*SD. Therefore‚ we can get the maximum order units for each style
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Student Exploration: Sight vs. Sound Reactions Vocabulary: histogram‚ mean‚ normal distribution‚ range‚ standard deviation‚ stimulus Prior Knowledge Questions (Do these BEFORE using the Gizmo.) Most professional baseball pitchers can throw a fastball over 145 km/h (90 mph). This gives the batter less than half a second to read the pitch‚ decide whether to swing‚ and then try to hit the ball. No wonder hitting a baseball is considered one of the hardest things to do in sports! 1. What
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histogram of the 1990 returns. (ii) Produce a histogram of the 1998 returns. (iii) Find the mean‚ median‚ range and standard deviation for the 1990 returns. Annual Returns % (1990) Mean 12.91865979 Median 11.38 Standard Deviation 9.297513067 Range 75.01 (iv) Repeat part (iii) for the 1998 returns. Annual Returns % (1998) Mean 6.355463918 Median 5.4 Standard Deviation 5.170830853 Range 42.76 (v) Which was the better year for investors? • 1990 was the better year for investors in
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A. What is the mean age of this sample? What is the standard deviation? The mean age is 47.5 years old. The standard deviation is 10.74832 years. http://www.calculator.net/standard-deviation-calculator.html Sample Standard Deviation‚ s: 10.748316881702 Sample Standard Variance‚ s2 115.52631578947 Total Numbers‚ N 20 Sum: 950 Mean (Average): 47.5 Population Standard Deviation‚ σ 10.476163419878 Population Standard Variance‚ σ2 109.75 If it follows the normal distribution The
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m and the women have a mean height of 1.62 m. Find the mean height of the 100 mathematicians. (Total 4 marks) 3. The mean of the population x1‚ x2‚ ........ ‚ x25 is m. Given that = 300 and = 625‚ find (a) the value of m; (b) the standard deviation of the population. (Total 4 marks) 4. A supermarket records the amount of money d spent by customers in their store during a busy period. The results are as follows: Money in $ (d)|0–20|20–40|40–60|60–80|80–100|100–120|120–140| Number of
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13. Variance and Standard Deviation (expected). Using the data from problem 13‚ calculate the variance and standard deviation of the three investments‚ stock‚ corporate bond‚ and government bond. If the estimates for both the probabilities of the economy and the returns in each state of the economy are correct‚ which investment would you choose considering both risk and return? Why? ANSWER Variance of Stock = 0.10 x (0.25 – 0.033)2 + 0.15 x (0.12 – 0.033)2 + 0.50 x (0.04 – 0.033)2 + 0
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